PROBLEM TO BE SOLVED: To provide an endoscope system capable of accurately calculating oxygen saturation even if there is dirt adhering to an observation object, and also to provide an endoscope system processor device, an operation method for an endoscope system, and an operation method for an endoscope system processor device.SOLUTION: An endoscope system 10 comprises: an image signal acquisition unit 54 for acquiring a B1 image signal corresponding to blue narrowband light in which the light absorption quantity changes according to the oxygen saturation of blood hemoglobin, a G2 image signal corresponding to a green wavelength band in which the light absorption quantity changes according to a blood volume of an observation object, an R2 image signal corresponding to a red wavelength band in which a change in the light absorption quantity with respect to the oxygen saturation or the blood volume is small compared with the B1 and G2 image signals, and a B2 image signal of which difference in the center wavelength from the blue narrowband light is 20 nm or more and 100 nm or less； and an oxygen saturation calculation unit 83 for calculating the oxygen saturation of the observation object for each pixel on the basis of the B1, G2, R2, and B2 image signals.COPYRIGHT: (C)2016,JPO&INPIT【課題】観察対象に汚れが付着している場合でも正確な酸素飽和度を算出することができる内視鏡システム、内視鏡システム用プロセッサ装置、内視鏡システムの作動方法、及び内視鏡システム用プロセッサ装置の作動方法を提供する。【解決手段】内視鏡システム１０は、血中ヘモグロビンの酸素飽和度に応じて吸光量が変化する青色狭帯域光に対応するＢ１画像信号と、観察対象の血液量に応じて吸光量が変化する緑色波長帯域に対応するＧ２画像信号と、Ｂ１画像信号やＧ２画像信号よりも酸素飽和度や血液量に対する吸光量の変化が小さい赤色波長帯域に対応するＲ２画像信号と、青色狭帯域光に対して中心波長の差が２０ｎｍ以上１００ｎｍ以下のＢ２画像信号と、を取得する画像信号取得部５４と、Ｂ１画像信号と、Ｇ２画像信号と、Ｒ３画像信号と、Ｂ２画像信号とに基づいて、観察対象の酸素飽和度を画素毎に算出する酸素飽和度算出部８３と、を備える。【選択図】図７
